Basal and stress-induced salivary testosterone variation across the menstrual cycle and linkage to motivation and muscle power.

This study investigated salivary testosterone (sal-T) variation across the menstrual cycle in female athletes, at different competitive levels, and its association with motivation and neuromuscular power. Six elite and 16 non-elite female athletes were monitored on days 7 (D7), 14 (D14), and 21 (D21) across 3 menstrual cycles for basal sal-T concentrations and self-appraised motivation to train and compete. Two further measures were taken on D7, D14, and D21 across 2 menstrual cycles: (1) the sal-T response (delta change) to a physical stress test and (2) peak power (PP) response to a 6-second cycle sprint following a post-activation potentiation (PAP) stimulus. Basal sal-T concentrations increased by 17 ± 27% from D7 to D14 before decreasing by -25 ± 43% on D21 (P < .05), but this result was biased by elite females with higher sal-T (>102%) who showed larger menstrual changes. Motivation, sal-T reactivity to stress, and the PP responses to a PAP stimulus also varied by testing day (P < .05), in parallel with basal sal-T and in favor of the elite group. Furthermore, stronger within-subject relationships (P < .001) between basal sal-T and motivation emerged in the elites (r = .70-.75) vs the non-elite group (r = .41-.50). In conclusion, menstrual cycle changes in sal-T were more obvious in high-performing female athletes with higher sal-T concentrations. This was accompanied by greater training motivation, a more pronounced sal-T response to a physical stressor and greater neuromuscular power in the elite group. These results support observations that female athletes with higher T are more represented at elite levels of performance.

Temporal associations between individual changes in hormones, training motivation and physical performance in elite and non-elite trained men.

To advance our understanding of the hormonal contribution to athletic performance, we examined the temporal associations between individual changes in testosterone (T) and/or cortisol (C) concentrations, training motivation and physical performance in elite and non-elite trained men. Two male cohorts classified as elites (n = 12) and non-elites (n = 12) completed five testing sessions over a six-week period. The athletes were tested for salivary T, C, T/C ratio, self-perceived training motivation, countermovement jump (CMJ) height and isometric mid-thigh pull peak force (IMTP PF), after which an actual training workout was performed. The elite men reported higher motivation to train and they produced greater CMJ height overall, whereas the non-elites had higher pooled T levels (p < 0.05). No significant group differences in C concentrations, T/C ratio or IMTP PF were found. The individual changes in T levels were positively associated with training motivation in the elite men only (p = 0.033), but the hormonal and motivation measures did not predict CMJ height or IMTP PF in either group. The monitoring of elite and non-elite men across a short training block revealed differences in T levels, motivation and lower-body power, which may reflect training and competitive factors in each group. Despite having lower T levels, the elite athletes showed better linkage between pre-training T fluctuations and subsequent motivation to train. The nature of the performance tests (i.e. single repetition trials) could partly explain the lack of an association with the hormonal and motivational measures.

The effects of two equal-volume training protocols upon strength, body composition and salivary hormones in male rugby union players.

This study examined the effects of two equal-volume resistance-training protocols upon strength, body composition and salivary hormones in male rugby union players. Using a crossover design, 24 male rugby players completed a 4-week full-body (FB) and split-body (SB) training protocol of equal volume during the competitive season. One repetition maximum (1RM) strength, body composition via skinfold measurements and salivary testosterone (T) and cortisol (C) concentrations were assessed pre and post training. The FB and SB protocols improved upper (7.3% and 7.4%) and lower body 1RM strength (7.4% and 5.4%), whilst reducing body fat (-0.9% and -0.4%) and fat mass (-5.7% and -2.1%), respectively (all p ≤ 0.021). The SB protocol elevated T (21%) and C (50%) concentrations with a higher T/C ratio (28%) after FB training (all p ≤ 0.039). The strength changes were similar, but the body composition and hormonal results differed by protocol. Slope testing on the individual responses identified positive associations (p ≤ 0.05) between T and C concentrations and absolute 1RM strength in stronger (squat 1RM = 150.5 kg), but not weaker (squat 1RM = 117.4 kg), men. A short window of training involving FB or SB protocols can improve strength and body composition in rugby players. The similar strength gains highlight training volume as a key adaptive stimulus, although the programme structure (i.e. FB or SB) did influence the body composition and hormonal outcomes. It also appears that 1RM strength is associated with individual hormonal changes and baseline strength.

Trained and untrained males show reliable salivary testosterone responses to a physical stimulus, but not a psychological stimulus.

BACKGROUND: The testosterone (T) responses to a physical stimulus are thought to be more stable and reproducible compared to a psychological stimulus. PURPOSE: This study compared the salivary T (Sal-T) responses to both stimuli in four groups of men: professional rugby players (n = 17), recreational rugby players (n = 10), a mixed athlete group (n = 14) and untrained controls (n = 12). METHODS: Each group completed three treatments: (1) watching a video with aggressive rugby footage, (2) performing a short bout of sprint exercise and (3) a control session. Saliva samples were taken before and 15 min after each treatment. RESULTS: The sprint exercise changes in Sal-T levels were similar in the elite rugby (17.1 ± 11.1%), recreational rugby (11.9 ± 15.9%), mixed athlete (27.6 ± 32.0%) and control groups (25.3 ± 23.6%). In response to the video, Sal-T increased in the elite rugby (6.9 ± 6.4%) and untrained groups (11.9 ± 13.5%), but decreased in the recreational rugby players (-7.5 ± 11.0%). The individual Sal-T responses to the sprints were also correlated (r = 0.69 to 0.82) with other treatment responses. CONCLUSIONS: Sprint exercise had a more consistent effect on Sal-T than a video with aggressive content and thus, could provide a reliable stimulus for increasing T availability in men with different training backgrounds. Individual Sal-T reactivity also appears to be somewhat stable across different treatments. These data provide further understanding around the induction, moderation and interpretation of T physiology.

Strength and power predictors of sprinting performance in professional rugby players.

AIM: The ability to accelerate and attain high levels of speed is an essential component of success in team sports; however, the physical qualities that underpin these activities remain unclear. This study aimed to determine some of the key strength and power predictors of speed within professional rugby union players. METHODS: Twenty professional male rugby union players participated in this study. Subjects were tested for speed (0-10 m sprint and a flying 10 m sprint), strength (3 repetition maximum squat), lower body power (countermovement jumps [CMJ] and drop jumps [DJ]), reactive strength and leg spring stiffness. The strength and power variables were expressed as absolute values and relative values for analysis. RESULTS: Both relative strength (r=-0.55, P<0.05) and relative power (-0.82, P<0.01) were negatively correlated with 10 m time. Leg spring stiffness and DJ contact time were also related to the flying 10 m time (r=-0.46 and 0.47, respectively, P<0.05) while reactive strength index was negatively related to both the 10 m and flying 10 m times (r=-0.60 and r=-0.62, P<0.05). CONCLUSION: This study provides an insight into those physical attributes that underpin sprinting performance in professional rugby union players and specifically highlights the importance of relative strength and power in the expression and development of different speed components (e.g. acceleration, maximum velocity).

The effects of a resistance-training program on strength, body composition and baseline hormones in male athletes training concurrently for rugby union 7's.

AIM: To examine the effects of a resistance-training program on strength, body composition and baseline hormones in male athletes training concurrently for rugby union 7's. METHODS: Participants (N.=12) completed a six-week resistance-training program focusing on general strength development while still performing additional rugby union 7's training involving agility, speed and cardiovascular fitness. One repetition maximum (1RM) strength was assessed pre and post training across 5 exercises (bench press, back squats, deadlifts, military press and chins), along with body composition and baseline salivary testosterone (T) and cortisol (C) concentrations. RESULTS: Significant improvements in bench press (11%), back squat (13%), deadlift (13%), military press (10%) and chin-up (6%) 1RM strength were observed after training (P < 0.05). These changes were accompanied by a significant reduction (-1%) in body fat and an increase (1.3%) in fat-free mass. Baseline T and C concentrations and the T/C ratio did not change significantly with training (P>0.05). Correlational analyses indicated that most of the individual changes in strength, body composition and hormones were not significantly related. CONCLUSION: The implementation of a resistance-training program in male athletes already training for rugby union 7's led to all-round improvements in maximal dynamic strength even while they continued to perform other forms of rugby-specific training. These findings support the use of resistance exercise as a supplement to sport-specific training for improving the performance capacity of 7's rugby players.

Relationships between salivary free testosterone and the expression of force and power in elite athletes.

AIM: This study examined the predictive relationships between the salivary free testosterone (T) concentrations of elite athletes and the expression of force and power. METHODS: A group of elite male rugby players (N.=64) were assessed for peak force (PF), peak rate of force development (PRFD), force at 100 milliseconds (F100 ms) and 250 milliseconds (F250 ms) during an isometric mid-thigh pull (IMTP), and/or peak power (PP) and height during a countermovement jump (CMJ). Saliva samples were collected before testing and assayed for free T. Relationships between individual T concentrations and performance were assessed as a pooled group and 4 sub-groups of equal size. RESULTS: As pooled data sets, none of the IMTP and CMJ performance variables were significantly correlated with free T in either the PF or PP groups (r=0.01-0.23). The PF and PP abilities of the 4 sub-groups were significantly different, so that PF1>PF2>PF3>PF4 (P<0.001) and PP1>PP2>PP3>PP4 (P<0.01). When the 4 sub-groups were analysed, the T concentrations of the PF4 group were significantly (P<0.05-0.01) correlated to PRFD (r=0.69) and F100 ms (r=0.55) during the IMTP, as was F100 ms in the PF1 group (r=0.66). In the PP1 group, free T also correlated to CMJ height (r=0.62). CONCLUSION: The key conclusion is that the expression of force and power in an elite athletic group may be dependent, to some extent, on individual variation in salivary free T concentrations and existing strength or power levels. The current results also confirm that the grouping of elite athletes of mixed strength or power ability may bias predictive results in a manner not reflective of sub-groups within this population.

Scaling strength and power for body mass differences in rugby union players.

AIM: This study on professional rugby union players was undertaken to: 1) confirm a relationship between body mass (BM) and peak force (PF) and peak power (PP); 2) evaluate the effect of ratio and allometric scaling on these relationships; and 3) compare the PF and PP abilities of different positional groups with each approach. METHODS: Seventy-nine rugby players were assessed for PF during an isometric mid-thigh pull and/or countermovement jump PP. Athlete performance was normalized for BM using standard ratio and allometric scaling methods. The performance data from inside backs (IB), outside backs (OB), tight forwards (TF) and loose forwards (LF) were compared before and after scaling for BM. RESULTS: Significant relationships were identified between BM and the absolute expression of PF (r=0.25) and PP (r=0.44). These relationships improved with the application of ratio scaling (r=-0.53 to -0.57), but were eliminated after allometric scaling with the derived exponents (r=0.00-0.02). No positional group differences in absolute and allometrically scaled PF and PP were seen, but ratio scaled performance favoured the lighter IB and OB over the heavier TF and/or LF (P<0.05). CONCLUSION: The PF and PP abilities of professional rugby union players were related to individual BM and these relationships were differentially affected by ratio (enhanced) and allometric (removed) scaling. Ratio scaled performance favoured the lighter backs over the heavier forwards, which could be explained by their specific movement patterns within a game. Comparing positional data in such a manner may help practitioners to better quantify, assess and monitor the position-specific needs of athletes in team sport.

Validating two systems for estimating force and power.

This study examined the validity of 2 kinematic systems for estimating force and power during squat jumps. 12 weight-trained males each performed single repetition squat jumps with a 20-kg, 40-kg, 60-kg and 80-kg load on a Kistler portable force plate. A commercial linear position transducer (Gymaware [GYM]) and accelerometer (Myotest® [MYO]) were attached to the bar to assess concentric peak force (PF) and peak power (PP). Across all loads tested, the GYM and MYO estimates of PF and PP were moderately to strongly correlated ( P≤0.05-0.001) with the force plate measurements ( R=0.59-0.87 and R=0.66-0.97), respectively. The mean PF and PP values were not significantly different between the 2 kinematic systems and the force plate, but the estimates did produce some systematic bias and relatively large random errors, especially with the 20-kg load (PF bias >170 N, PF error >335 N, PP bias >400 W, PP error >878 W). Some proportional bias was also identified. In summary, the estimation of PF and PP by a linear position transducer and accelerometer showed moderate to strong relative validity and equivalent absolute validity, but these estimates are limited by the presence of bias and large random errors.

Effects of resistance training periodization on performance and salivary immune-endocrine responses of elite female basketball players.

AIM: The aim of this paper was to examine the effects of resistance training periodization on the performance and salivary hormone-immune responses of elite female basketball players. METHODS: Twelve female athletes were monitored across a 50 day period of resistance training that emphasized strength, endurance and power. One repetition maximum (1RM) strength, maximal repetitions at 50% 1RM and vertical jump performance was assessed pre- and post-training. Saliva samples were also collected at 0700, 0930, 1100 and 1730 hours and analyzed for testosterone (T), cortisol (C) and immunoglobulin A (IgA). RESULTS: Improvements in 1RM strength, maximal repetitions and vertical jump performance were identified post-training (P<0.05). Training had no effect on salivary T and C concentrations, but the T:C ratio increased at 0730 hours (P<0.05) and IgA concentrations were lowered at 0930 and 1100 hours (P<0.05). The changes (∆ Pre-Post training) in strength and T concentrations were positively correlated at 0730 hours (P<0.05). CONCLUSION: A periodized approach to resistance training increased muscle performance in elite female basketball players, but only minor changes in the salivary T:C ratio and IgA were noted. Correlational analysis identified a possible role for early morning changes in T as a regulator of individual strength changes.

Relationships between salivary testosterone and cortisol concentrations and training performance in Olympic weightlifters.

AIM: This study examined the relationships between salivary testosterone (Sal-T) and cortisol (Sal-C) concentrations and training performance in Olympic weightlifters. METHODS: Four male and four female Olympic weightlifters each provided saliva samples before and after four workouts during a four-week training period. Training involved the same three exercises; snatch, clean and jerk, and front squat with the one repetition maximum (1RM) calculated for each exercise during each workout. RESULTS: Significant (P < 0.05-0.01) training improvements in 1RM performance (4.0-5.2%) were noted during the snatch and clean and jerk exercises, along with the Olympic total lift. For male participants only, the pre-workout concentrations of Sal T were significantly (P < 0.05-0.01) correlated with the snatch (r = 0.70) and clean and jerk 1RM (r = 0.62), and the Olympic total lift (r = 0.66). CONCLUSION: A short period of training improved the 1RM performance of Olympic weightlifters in two exercises (snatch and clean and jerk) and the Olympic total. For male participants, their Sal-T concentrations before each workout was also related to 1RM performance during these exercises, thereby highlighting one possible short-term causative mechanism. Limitations of this study include the short duration of hormonal monitoring, the limited number of workouts assessed and the small number of participants recruited. Also, correlations between the outcome variables still only reflect casual associations.

Measuring the salivary testosterone and cortisol concentrations of weightlifters using an enzyme-immunoassay kit.

This study assessed an enzyme-immunoassay (EIA) kit for measuring the salivary testosterone (T) and cortisol (C) concentrations of weightlifters. Saliva samples (n=64) were collected from male and female weightlifters during normal training procedures and analysed for T and C using a commercial EIA kit and a criterion radioimmunoassay (RIA) method. Significant correlations were demonstrated between the EIA and RIA measurements of salivary T (r=0.72) and C (r=0.96) [corrected] concentrations (P<0.001). Further examination by sample and gender revealed similar relationships. The EIA concentrations of salivary T and C were found to be slightly greater (10-13%) than the RIA values. Similar discrepancies were noted when gender comparisons were made, although the relative information on T (males > females) and C (males=females) were consistent for both assay methods. In conclusion, a commercially available EIA kit provided valid measures of the salivary T and C concentrations of male and female weightlifters. Factors to consider when using an EIA kit include the hormone(s) of interest, the magnitude of the correlations, as well as the descriptive information gained (e. g. absolute, relative) and its uses within sport.

Validating the salivary testosterone and cortisol concentration measures in response to short high-intensity exercise.

AIM: To validate the testosterone (T) and cortisol (C) concentration measures in saliva in response to short high-intensity exercise. METHODS: Nine healthy males provided matching saliva and plasma samples before and after a 30-second Wingate cycle test. Saliva was assayed for T (Sal-T) and C (Sal-C) concentrations, and plasma for total T and total C, sex hormone-binding globulin, corticosteroid-binding globulin (CBG) and albumin concentrations. The plasma free and bioavailable hormones were calculated. RESULTS: The Sal-T and plasma T correlations were weak to moderate (r=0.57-0.61) when examined between individuals (pooled data for all participants), but these relationships improved (r = 0.71-0.73) within individuals (data for each participant on average). The Sal-C and plasma C correlations were strong both between individuals (r=0.81-0.84) and within individuals (r=0.83-0.84). The peak relative increases in Sal-T (35+/-9%) and Sal-C (63+/-29%) concentrations exceeded the plasma total and/or free hormones, but not the bioavailable hormones. Albumin (10+/-3%) and CBG (16+/-4%) also increased with exercise, along with blood lactate (943+/-119%). CONCLUSION: The Sal-T and Sal-C concentration measures were validated in response to short high-intensity exercise, especially for individuals. The hormonal changes in saliva were also more sensitive to exercise (i.e. greater relative responses) than the plasma total and/or free hormones, potentially arising from changes in the binding proteins and blood lactate. These findings support the use of saliva as a medium for steroid determination in sport.